Echinacea plants have been used medicinally for many years and today, Echinacea preparations are sold worldwide. Various methods for the isolation of these compounds have been used including, for example, extraction with organic solvents, and isolation by column chromatography and thin layer chromatography. However, none of the processes developed so far are suitable for production scale manufacturing. Furthermore, up until recently, the quality and efficacy of Echinacea preparations has been unreliable and research results using them have been contradictory. For example, some researchers have reported that alkamides (also referred to as alkylamides or isobutylamides) have immunostimulatory activity (Y. Goel et al., Alkylamides of Echinacea purpurea stimulate alveolar macrophage function in normal rats. International Immunopharmacology 2:381-387 (2002)), while others report alkamides to have immunosuppressive activity in vitro as evidence by the inhibition of cyclooxygenase and 5-lipoxystimulatory activities (B. Muller-Jakic et al., In vitro inhibition of cyclooxygenase and 5-lipoxygenase by alkamides from Echinacea and Achillea species. Planta Medica 60:37-40 (1994); R. Bauer et al., Echinacea species as potential immunostimulatory drugs. Economic and Medicinal Plant Research 5:253-321 (1991)).
Commercially available Echinacea products are typically found to have both immunosuppressive and immunostimulatory components. For example, the preparations disclosed in U.S. Pat. Nos. 6,511,683 and 6,447,815 contain both bioactive components. U.S. Pat. No. 6,511,683, proposes to provide compositions composed of Echinacea polysaccharides, Echinacea alkylamides and cichoric acid and methods for preparing such compositions. This patent also proposes to provide compositions enriched in at least one Echinacea component. The method involves selecting Echinacea plants at a particular stage of development having an enhanced amount of desired component and further selecting a portion of the plant that is enriched in the desired component. However, the method of extraction remains the same and the extracts continue to have both immunostimulatory and immunosuppressive components. U.S. Pat. No. 6,447,815, proposes a method of extracting herbs and plant material including Echinacea wherein higher yields of marker compounds such as alkamides, may be obtained. However, Echinacea compositions prepared by this method are found to contain both immunostimulatory and immunosuppressive components.
Currently, there remains a need to provide a method of producing preparations of Echinacea anti-inflammatory and immunosuppressive components including alkamides, which do not also contain immunostimulatory components. The present invention discloses a method of preparing an Echinacea composition at a production scale level that contains only the anti-inflammatory and immunosuppressive components such as the alkamides, polyacetylenes and fatty acids and does not contain the immunostimulatory components such as cichoric acid, echinacoside, polysaccharides and glycoproteins. The methods of this invention produce an Echinacea composition having anti-inflammatory and immunosuppresive activity that can be used, for example, for the treatment of colds, flu, and other upper respiratory tract infections, inflammatory diseases and immunomodulatory disorders.